When you get a request for cross-promotion, you can see the metrics of that site (traffic, niche, age etc). If the metrics aren't to your liking, you can simply decline the cross-promotion request.

Also, it's actually not about exchanging links - in fact, we strongly encourage all users on our platform to nofollow the links. This is about teling your readers "Hey! There's this interesting blog you should check out" - and getting the same in return.